Help tuning amp and fixing subs?

I have one 10 inch pioneer championship series pro sub in a ported box and the bass is loud but it doesn't kick at all, i guess you call that distorted? My amp is a Pioneer mono 800 watt max, and im pretty sure it is set to 400w x 2 but i don't know how to find that out or if it is automatic with your sub and radio. My head unit is a Pioneer also so how should i set the amp and radio to where the sub only kicks to the low bass and doesn't rumble to the high bass. my amp has a ; LPF switch (On/off), LPF knob (40hz-240hz), gain(6.5-.2, bass boost (0, +6, +12), My head unit has bass (0 - +6), Sub w.1 (-24- +6), sub w.2 (50hz-125hz), equalizer (5 band), hpf (off, 50-125), and loud.

How should I set these to get a nice kick (i am tired of the loud distorted high pitched bass i have it set to) it doesn't have to be that loud just to where i can hear a nice low kick, rather than a high rumble.

so basically my questions are

1. how to tune this entire system? (please and thank you)

2. does a loud rumble where all the bass is the same, mean distorted?

3. the box is ported and i'm pretty sure that it is a big problem (even if the amp and everything is low, it still makes an annoying rumble). anything i can do to fix that or will tuning help?

4. Can i add something to the box, or do anything to seal it?

5. Lastly how do i know whether my amp is set at 800w x 1, or 400w x 2 or any of that?

please help i hate this annoying rumbling and i want a kick to the system?